The converters cost several hundred dollars to replace, but the thieves caused extensive damage to three of the vehicles while removing them, said Sgt. Steve Bevens of the Troutdale Police Department. Workers realized something was wrong when they started the vehicles and found exhaust problems.

This marks the third time in the past 30 days thieves have targeted converters in Troutdale, though it's the first time the city has been hit.

Bevens said scrap-metal thieves can resell the converters for $75 to $100 apiece. The devices that reduce all things ugly come with a hidden treasure.